A solution contains Fe ²⁺, Fe ³⁺ and I ⁻ ions. This solution was treated with iodine at 35^ C . E^ for Fe ³⁺ / Fe ²⁺ is +0.77 ~V and E ^ for I ₂ / 2 I ⁻=0.536 ~V . The favourable redox reaction is

Step-by-step solution

2 I ⁻ I ₂+2 e⁻ (Oxidation half-reaction) E_ oxi. ^ =-0.536 ~V . Fe ³⁺+e⁻ Fe ²⁺ (Reduction half-reaction) aligned E^ & =E_ oxi ^ +E_ red ^ & =+ ve aligned So, reaction will take place.